LAUSR

Abstract In HL-2 M tokamak, three-phase thyristor power supplies are utilized to output a direct current to energize the device coil to control the plasma current and shape configuration. Phase-controlled is currently the most effective control method in thyristor power supply. The quality of the synchronization signal is directly related to the performance of the thyristor power supply control. HL-2 M device uses a pulse generator with rectifier load to supply power to the device coil, it makes the thyristor power supply AC input voltage not only have a wide frequency variation but also a severe waveform distortion, so it is difficult to obtain the accurate synchronization signal of the thyristor power supply. In this paper, a real-time tracking and processing method for variable frequency synchronization signals are proposed, which applied the digital filter with point-to-point to process varying frequency synchronization signal, calculated the real-time frequency of the filtered data, obtained the delay angles at different input frequencies according to the phase-frequency characteristics of Butterworth low-pass filter, and reconstructed the synchronization signal by phase compensation. The system has been built to achieve a wide range of real-time frequency tracking from 70 to 110 Hz, and provides multiple synchronization signal output with 15° interval. The performance of the system was verified in the HL-2A experiment.